1. Field of the Invention
The invention relates to an outer ring of a tapered roller bearing, a tapered roller bearing, and a manufacturing method of an outer ring of a tapered roller bearing.
2. Description of the Related Art
Japanese Patent Application Publication No. 11-48805 (JP-A-11-48805) describes a tapered roller bearing. This tapered roller bearing rotatably supports a pinion shaft of a differential gear unit with respect to a housing of the differential gear unit.
This tapered roller bearing includes an outer ring, an inner ring, and a plurality of tapered rollers. The outer peripheral surface of the outer ring is fixed fitted to the inner peripheral surface of the housing. Meanwhile, the inner peripheral surface of the inner ring is fixed fitted to the outer peripheral surface of the pinion shaft. The plurality of tapered rollers is arranged with spaces between them in the circumferential direction, in a state retained by a retainer, between a tapered raceway surface of the outer ring and a tapered raceway surface of the inner ring. The outer ring of the tapered roller bearing is solid.
However, because the outer ring is solid, the tapered roller bearing is unable to trim weight, and when used in a vehicle, the operating costs and material costs increase.
Also, because the outer ring of the tapered roller bearing is solid, the grinding amount is large and the grinding time is long, so manufacturing costs increase.